1. Field of the Invention
The invention relates to a method and an apparatus for the manufacture of a workpiece having a rotation-symmetrically hardened surface area.
2. Description of the Related Art
Surface areas of metallic workpieces are hardened in order to increase the wear resistance of the surface areas exposed to increased stress. Numerous surface hardening methods, such as hardening in a heating furnace, nitriding by diffusing in nitrogen, or chroming, are known. In all these methods, the workpiece must be shaped prior to hardening. After hardening the workpiece geometry can scarcely be modified, or such modifications increase costs. In the aforementioned methods, there is a risk of an undesired, geometrical change to the workpiece due to thermal distortion or a nonuniform coating deposition, so that such methods are difficult to put into effect for the manufacture of dimensionally accurate workpieces. Finally, such methods can only be performed using special manufacturing apparatuses.